There are several options for restoring speech to patients who have had their larynx removed. One procedure is to surgically create a puncture or fistula between the trachea and the esophagus. A trachea voice prosthesis containing a one-way valve such as a BLOM-SINGER.RTM. voice prosthesis is inserted into the tracheoesophageal fistula. The one-way valve protects the airway during swallowing but opens under positive pressure. The voice prosthesis, thus, permits a patient to divert air from the lungs into the esophagus and out through the mouth. Speech is created during passage of air through the upper part of the esophagus.
The prosthesis maintains the fistula open, transfers air from the trachea to the esophagus for voice production and prevents esophageal leakage into the trachea during swallowing. However, the prosthesis being in contact with moisture in a hot, dark environment is subject to growth of commonly found yeast formation, typically Candida Albicans on the valve and the retaining flange. The growth of yeast can interfere with function of the valve and can cause the flange to wrinkle and leak.
The current low pressure voice prosthesis can be removed by the patient every few days and can be replaced with a clean prosthesis. The removed prosthesis is soaked in hydrogen peroxide to remove the layer of yeast from the valve and flange. Some patients however, have difficulty managing frequent removal and reinsertion of the prosthesis. Others, who are physically handicapped are not able to remove, sterilize, or reinsert the prosthesis.
A longer dwelling, low pressure voice prosthesis has been developed that can remain in place in the tracheoesophageal fistula for over 3-4 days, depending on the patient and conditions of use. The patient can confidently use the prosthesis for longer periods. Trips to a health care specialist to remove and replace the prosthesis are greatly extended providing increased comfort and lower cost to the patient.
The flange or collar that rests against the tracheoesophageal wall is strengthened by increasing the thickness and/or diameter of the flange. The stronger flange is more resistant to wrinkling or detachment from the wall. The voice prosthesis can remain in place in the fistula for much longer periods without allowing leakage between the trachea and the esophagus. The stronger and larger collar also reduces possibility of dislodgment of the prosthesis during a coughing or sneezing episode.
However, the thicker and wider flange is more difficult to insert though the fistula and does not reliably seat on the tracheoesophageal wall. An insertion system as disclosed in U.S. Pat. No. 5,300,119, the disclosure of which is incorporated herein by reference, can be utilized to insert the long dwelling voice prosthesis into the fistula. The thicker flange is folded toward the axis of the tube of the prosthesis and inserted into a gelatin capsule, which is inserted through the fistula. Moisture in the esophagus dissolves the capsule which releases the folded flange which is intended to deploy and seat against the tracheoesophageal wall.
Seating of the retention collar against the anterior wall of the esophagus can be confirmed by rotating the inserted prosthesis within the puncture. Correctly and securely inserted prosthesis will rotate freely, repeatedly through 360.degree.. If the prosthesis does not rotate freely, it suggests that the retention collar has not unfurled and seated. The flange does not fully open and seat in every instance. The body of the prosthesis may be too short or a portion of the flange may be caught in the fistula. A system for radiographic assessment for direct confirmation that the prosthesis is correctly seated is disclosed in copending application Ser. No. 08/282,277 filed on Jul. 27, 1994, the disclosure of which is expressly incorporated herein by reference.
Yeast growth on the valve can also cause distortion of the shape of the valve or form wrinkles in the body of the valve which prevents the valve from closing.
Leaking also appears to be due to distortion of the valve body adjacent to the seat of the valve and to yeast growth on the seat. Forming the valve with an arcuate dome shape increased resistance to folding or bending of the valve. However, some valves still leaked after extended placement in a fistula.